Lock with universal key ejector

ABSTRACT

A tumbler lock having associated therewith a spring-biased key ejector which is effective to eject the key in all angular positions of the plug, i.e., in the unlocked position, the locked position, or any intermediate position so that at no time may the key be left within the lock.

i Untted States Patent 1151 3,661,000 Kerr 1 1 May 9, 1972 [s41 LOCKWITH UNIVERSAL KEY 1,820,747 10/1931 Perry ..200/42 EJECTOR 3,552,1601/1971 Kleebauer ..70/388 1.946.722 2/1934 Thompson... 70/388 [72]Inventor. William .1. Kerr, G1env1ew, 111. 1.422.594 7H9 Maxwell IIIIum/375 x [73] Assignee: Chicago Lock Co., Chicago, Ill. 1,968,555 7/1934Horne..... ....70/375 X [22] Filed: June n 1970 1.738.105 12/1929.lacob1 v.70/388 [2|] AppLNo; 45,698 Primary Examiner-Robert L. W011:

Attorney-Norman H. Gerlach [52] US. Cl. ..70/388 511 [111.121 ..E05b17/00 1 1 ABSTRACT Search A umbler lock having associated therewith asprins biased 70/376 370 key ejector which is effective to eject the keyin all angular Rdermm cued postttons of the 1ug.1.e.,1n the u 11ockedposmon, the locked posmon. or any 1ntermed1ate position so that at 110um: may UNTED STATES PATENTS the key be left within the lock.

3,492,843 2/1970 Schieber ..70/388 9 Claims, 6 Drawing Figures 1.1: r L1111 f? 1' 1 W/ 1 l I I L Y 1 9 f2 4 a \B2 LOCK wrrn UNIVERSAL KEYmacros The present invention relates to a key-controlled lock of thetype in which a plug having a keyway therein is rotatable within a lockcylinder, the usual tumblers being employed to lock the plug againstrotation with respect to the encompassing lock cylinder. The inventionis specifically concerned with key-ejecting means whereby the key is atall times biased against forward movement in the keyway in the plug sothat at any time the key is released, regardless of whether the plug bein its locked position, its unlocked position, or in any intermediateposition, it will be automatically ejected from the keyway andconsequently, from the lock as a whole.

The improved lock comprising the present invention is designed primarilyfor use in connection with a refrigerator cabinet, especially a cabinetof the deep freeze type. Such a cabinet usually is kept in a basementwhere it is accessible to children, and there are on record numerousinstances of fatalities arising from children at play and in thepossession of a key inadvertently left in a freezer cabinet. Suchinstances have led to recent regulations in certain states that not onlyshall a freezer cabinet lock intended for home use be devoid of a springlatch which would permit a given cabinet to become locked automaticallyupon closing the door or lid itself, but also that a cam type lock whichrequires a key for the locking thereof shall be provided with facilitieswhereby the key shall be automatically ejected from the lock.

The present invention goes a step further in this direction ofprecautionary safety in that it provides a lock in which it isimpossible to leave the key within the keyway in the rotatable plugregardless of whether the plug be in its unlocked position, its lockedposition, or in any intermediate position. I-Ieretofore, a lock of thekey-ejecting type has been designed primarily for automotive use and isso constructed that ejection of the key takes place only when therotatable plug of the lock is in either its locked or its unlockedposition. Such a lock, if applied to a freezer cabinet could.conceivably, be left in a partially locked condition where the key wouldbe readily available to a child.

A specific limitation that is attendant upon the construction and use ofa prior key-ejecting lock resides in the use of a keyloading springwhich necessitates the use of considerable manual pressure to overcomeits biasing action during insertion of the key into the keyway in theplug of the lock. Space limitations have dictated that such a spring beprovided with a relatively short length if it is coaxially disposed withrespect to the lock cylinder or that it be offset in a special chamberalongside of the cylinder. A short spring obviously is quickly loaded tocapacity and thus requires considerable force to drive the key to itshome position for tumbler-actuating purposes while an offset springresults in a bulky and expensive lock structure as a whole.

The present invention obviates the above-noted limitations that areattendant upon any prior key-ejecting lock, and toward this end, itcontemplates the provision of a lock in which the key ejector spring isof relatively small diameter and relatively long, as well as beingcoaxial with the rotatable, tumbler-equipped plug and its surroundingcylinder. The difficulties which ordinarily would be associated with theinstallation of such a long spring within the confines of the lock areobviated by making the plug in two separable parts so that the springmay be installed in a comparatively deep bore in one of the lock parts,the two parts assembled upon each other, and the assembled plug theninserted in the lock cylinder and held in place by a snap ring or thelike.

Insofar as ejection of the key in all angular or rotational positions ofthe plug within the cylinder is concerned, the use of constantlydiminishing hitting on the key allows key ejection at any time inasmuchas inward tumbler displacements which are maintained by the slidingaction of the outer ends of the tumblers against the interfacialcylindrical wall of the lock cylinder do not place the inside edges ofthe tumblers in the path of high hitting on the key.

The provision of a tumbler lock of the key-ejecting type such as hasbriefly been outlined above and possessing the stated advantages,constitutes the principal object of the present invention.

The provision of a key-ejecting lock which is appreciably simpler in itsconstruction than other key-ejecting locks designed for the same generalpurpose; one which is comprised of a minimum number of parts and,therefore, is unlikely to get out of order; one which is capable of easeof assembly for purposes of inspection or repair of parts; one which isrugged and durable and will, therefore, withstand rough usage and onewhich, otherwise is well adapted to perform the services required of it,are further desirable features which have been borne in mind in theproduction and development of the present invention.

Other objects and advantages of the invention, not at this timeenumerated, will become apparent as the nature of the invention isbetter understood from a consideration of the following detaileddescription.

The invention consists in the several novel features which arehereinafter described and more particularly defined by the claims at theconclusion hereof.

In the accompanying single sheet of drawings forming a part of thisspecification, one illustrative embodiment of the invention is shown.

In these drawings:

FIG. 1 is a longitudinal sectional view taken centrally andlongitudinally through a key-ejecting lock embodying the principles ofthe present invention and showing the key in position within the keywayin the rotatable plug of the lock;

FIG. 2 is a longitudinal sectional view similar to FIG. l but showingthe key released, and as a result thereof, ejected from the keyway inthe lock plug;

FIG. 3 is a longitudinal sectional view taken on the line 3-3 of FIG. 2;

FIG. 4 is a fragmentary front end view of the lock;

FIG. 5 is a transverse sectional view taken on the line 5-5 of FIG. 3;and

FIG. 6 is a transverse sectional view taken on the line 6-6 of FIG. 3.

Referring now to the drawings in detail, a lock embodying the presentinvention is designated in its entirety by the reference numeral 10 andincludes a tubular lock cylinder 12 having an enlarged head 14 at itsforward end, the head presenting a rearwardly facing radial shoulder 16.The outer periphery of the cylinder 12 may be threaded to the end thatthe cylinder may be secured in a lock-receiving opening in a cabinetdoor (not shown) by means of a nut 18 which draws the shoulder 16 firmlyagainst the front side of the door.

The cylinder 12 is provided with a longitudinally extendingplug-receiving bore 20 in which there is rotatably disposed a two-partseparable composite plug 14 see FIG. 3) including a front part 26 havingdiametrically slidable spring-pressed plate tumblers 28 associatedtherewith, and, in addition, a longitudinally extending keyway 30 forreceiving a single bitted key 32 which is configured to displace theplate tumblers 28 and enable rotation of the composite plug 24 in theusual manner of a plate tumbler type of lock. The key 32 is providedwith special hitting 34 which is of a progressively diminishing natureand, hence, is non-undulatory. Such hitting performs a particularfunction in connection with the key-ejection facilities of the lock aswill be described subsequently.

The forward region of the bore 20 is provided with a series of fourlongitudinally extending grooves 36 (see FIG. 5) which are disposedapart. One of these grooves is adapted to receive certain ends of theplate tumbler 28 when the plug 24 is turned so that the lock is in itslocked position, while another and adjacent groove is adapted to receivesaid certain ends of the plate tumblers when the plug is turned so thatthe lock is in its unlocked position. When the key 32 is fully disposedin the keyway 30, the tumblers are retracted so that the plug 24 may berotated.

The front end of the lock cylinder 12 has a counterbore 40 in which isseated a radial rim flange 42 on the front plug part 26. The rear sideof the rim flange 42 is relieved along one-half of its circumferentialextent to provide a pair of radially extending shoulders 44 and 46 (seeHO. 4) which are designed for cooperation with a pair of lugs 48 and 50in limiting the extent of plug rotation to 90.

The key 32 is provided with the usual longitudinal grooves 52 and 53 onopposite sides thereof and they cooperate with longitudinally andinwardly extending ribs 54 and 55 which are formed on the front plugpart 26 and extend along the keyway so that only a key having aparticular pattern of side grooves may be used in connection with thelock.

The general arrangement of parts thus far described is more or lessconventional and no claim is made herein to any novelty associated withthe same, the novelty of the present invention residing rather in thekey-ejecting mechanism by means of which the key 32 is prevented fromremaining in the keyway 30 regardless of the angular position of theplug 24 with respect to the cylinder 12.

The composite plug 24, in addition to the front part 26, comprises arear part 60 which is of elongated design and is connected to the frontpart 26 for rotation in unison therewith by means of a transverse tongueand groove connection including a T-head and T-slot interlock 62 (seeFIG. 3), the union being such that in the absence of any obstruction thetwo plug parts may be displaced laterally by a sliding movement betweenthe parts and then separated.

Slidably disposed in the keyway 30 is a key ejector element 64 whichresembles to a certain extent a forward or distal fragment of the keybitting 34. This key ejector element is capable of slidinglongitudinally in the keyway 30 by reason of a longitudinal groove 66which is formed therein on one side only and conforms to the key groove52. Said key ejector element 64 is yieldingly biased forwardly in thekeyway 30 by means of an elongated helical compression spring 70 whichis nested within a small but deep longitudinally extending and centrallydisposed socket 72 in the rear plug part 60. Said socket has sidegrooves 73 which constitute clearance regions for sliding movement ofthe key ejector element 64 when the latter is pushed rearwardly by thekey 32. A snap ring 74 in an annular groove 75 in the outer periphery ofthe rear plug part 60 cooperates with the rear end surface of thecylinder 12, and in combination with the rim flange 42, maintains thecomposite plug 24 in position against axial shifting with respect tosaid cylinder.

The rear end of the rear plug part is provided with the usualnon-circular, screw-threaded, reduced portion 76 for reception thereoverof a comformably shaped opening 78 in the inner end of a radiallyextending locking cam 80. A nut 82 holds the cam in plate on the reducedportion 76, the cam 80 being designed for cooperation with a suitablelocking shoulder on the cabinet in the vicinity of the door to which thelock is applied.

In the operation of the herein described lock 10, assuming the lock tobe in its locked position, insertion of the key 32 into the keyway 30will effect end-to-end engagement between the key and the key ejectorelement 64, thereby forcing the latter rearwardly in the side grooves 73and compressing the spring 70,while at the same time, subjecting the keyto a forward biasing action against the exerted manual pressure. As soonas the key reaches its home position, the various plate tumblers 28 willassume positions which release the composite plug 24 so that it may berotated by means of the key in the usual manner of lock operation. Thisforward biasing action against the key 32 remains prevalent throughoutthe full extent of turning movement of the plug 24 while it is beingturned to its unlocked position and it also remains effective after suchposition has been reached. By reason of the constant forward bias whichis thus applied to the key, and by reason of the fact that the keybitting 34 is of a constantly diminishing stepped and non-undulatorynature as previously set forth, no obstruction is offered to the key sothat if, at any time, it is manually released, it will be ejected fromthe keyway 30.

The fashioning of the lock plug 24 in two interlocking parts facilitatesinitial assembly of the lock, insertion of the spring 70 in the socket72 being effected before a union of the front and rear plug parts 26 and60 is made. Thereafter, by holding the key ejector element 64 retractedin the grooves 73, the T- head and T-slot connection may be effected,and upon release of the key ejector element 64, the extreme front end ofthe latter moves into engagement with the rib 55 near the front end ofthe front plug part 26 and prevents further movement of the key ejectorso that the latter assumes the position in which it is shown in H6. 2.Such engagement of the key ejector element 64 with the spline rib 55takes place by reason of the fact that one side of the key ejectorelement is devoid of a cooperating side groove. A forwardly presentedshoulder 84 on the key ejector element has no function in connectionwith key ejection, but is provided to facilitate manual retraction ofthe element during lock assembly and dismantlement operations.

From the foregoing description, taken in conjunction with theaccompanying drawings, it will be apparent to those skilled in the artthat this invention constitutes a substantial improvement inkey-controlled locks having key-ejection facilities, the improvementresiding largely in the fact that key-ejection takes place whenever thekey is manually released and regardless of whether the lock be in itslocked position, its unlocked position, or any intermediate position ofplug angular-ity.

The invention is not to be limited to the exact arrangement of partsshown in the accompanying drawings or described in this specification asvarious changes in the details of construction may be resorted towithout departing from the spirit or scope of the invention. Forexample, although the exemplary lock shown and described herein is ofthe plate tumbler type, it is obvious that with but slight modificationthe key-ejection facilities of the lock may be applied to pin tumblerlocks. Furthermore, it is obvious that by utilizing a double-bitted keyand causing the plate tumblers 28 variously to be springbiased inopposite directions, the two pairs of diametrically disposed grooves 36may be utilized for tumbler-receiving purposes when the plug 24 is inits locked and its unlocked positions, respectively. Therefore, onlyinsofar as the invention is particularly pointed out in the accompanyingclaims is the same to be limited.

Having thus described the invention what I claim as new and desire tosecure by letters patent is:

l. A lock and key combination comprising a lock cylinder. a plug havinga keyway and rotatably mounted in said cylinder, a key receivable insaid keyway, spring-pressed tumbler means movable in said plug andcylinder for preventing relative movement between the plug and cylinderwhen the key is removed from the keyway, a key-ejector element slidablydisposed in said keyway and having its front end engageable with thedistal end of the key for key-ejection purposes when the latter isinserted in the keyway, said key being formed with a longitudinal groovein one side thereof and the plug being formed with a cooperatinglongitudinal rib for guiding the key in the keyway, said rib beingpositioned in the path of forward movement of the key ejector elementand serving to limit the extent of forward movement of which the latteris capable, said key being further provided with tumbler-engagingbitting thereon of a constantly diminishing, non-undulatory naturewhereby said tumbler means offers no resistance to key-ejection by saidkey-ejector element regardless of the rotational position of the plugWithin the cylinder.

2. A lock and key combination as set forth in claim 1 and wherein thekey is formed with a longitudinal groove on the other side thereof, theplug is formed with cooperating longitudinal ribs on opposite sides ofsaid keyway, and the keyejector element is formed on one side thereofwith a longitu dinal groove which cooperates with one of said ribs onthe plug, the other side of the key-ejector element being devoid of agroove in order that the other rib on the plug is engageable with theforward end of the key-ejector element to limit the extent of forwardmovement of which said element is capable.

3. A lock and key combination as set forth in claim 2 and wherein thelock cylinder and plug define therebetween a cylindrical interface, thetumbler means includes a plurality of diametrically shiftable platetumblers which are springpressed so as to slide on the interfacialregion of the lock cylinder, and said interfacial region is formed withtwo circumferentially spaced longitudinal tumbler-receiving grooves, oneof which receives the tumblers when the plug is in its locked positionand the other of which receives the tumblers when the plug is in itsunlocked position.

4. A lock and key combination as set forth in claim 1 and wherein saidspring means comprises a compression spring which is nested within alongitudinally and centrally disposed socket in the plug. the rear endof the spring bearing against the bottom wall of the socket and thefront end thereof bearing directly against the front end of the keyejector element.

5. A lock and key combination as set forth in claim 4 and wherein theplug is of a composite nature and embodies a front plug part and a rearplug part having means releasably securing the parts together in coaxialend-to-end abutting relationship, and the socket within which thecompression spring is nested is formed in said rear plug part.

6. A lock and key combination as set forth in claim 8 and wherein saidreleasable securing means for the front and rear plug parts is in theform of a tongue and groove interlock connection between the parts.

7. A lock and key combination as set forth in claim 6 and wherein saidinterlock connection comprises a T-head on the rear plug part and aconformable T-slot in the rear end of the front part.

8. A lock and key combination as set forth in claim 5 and wherein thefront rim of the lock cylinder is provided with an annular recesstherearound, the front end of the front plug part is provided with a rimflange which seats within said annular recess, the rear plug part isprovided with an exterior annular seating groove in the vicinity of therear rim of the rear plug part, and a snap ring seats within said lattergroove and, in combination with said rim flange, serves to maintain theplug and lock cylinder in their assembled relation and against relativeaxial shifting.

9. A lock and key combination as set forth in claim 8 and wherein boththe key and the key ejector element are of flat plate-like commotion,are at all times coplanar, and the socket in which the compressionspring is nested is provided with a pair of diametrically disposedgrooves within which the opposite sides of the key ejector element isslidable.

41 I I t t

1. A lock and key combination comprising a lock cylinder, a plug havinga keyway and rotatably mounted in said cylinder, a key receivable insaid keyway, spring-pressed tumbler means movable in said plug andcylinder for preventing relative movement between the plug and cylinderwhen the key is removed from the keyway, a key-ejector element slidablydisposed in said keyway and having its front end engageable with thedistal end of the key for key-ejection purposes when the latter isinserted in the keyway, said key being formed with a longitudinal groovein one side thereof and the plug being formed with a cooperatinglongitudinal rib for guiding the key in the keyway, said rib beingpositioned in the path of forward movement of the keyejector element andserving to limit the extent of forward movement of which the latter iscapable, said key being further provided with tumbler-engaging bittingthereon of a constantly diminishing, non-undulatory nature whereby saidtumbler means offers no resistance to key-ejection by said key-ejectorelement regardless of the rotational position of the plug within thecylinder.
 2. A lock and key combination as set forth in claim 1 andwherein the key is formed with a longitudinal groove on the other sidethereof, the plug is formed with cooperating longitudinal ribs onopposite sides of said keyway, and the key-ejector element is formed onone side thereof with a longitudinal groove which cooperates with one ofsaid ribs on the plug, the other side of the key-ejector element beingdevoid of a groove in order that the other rib on the plug is engageablewith the forward end of the key-ejector element to limit the extent offorward movement of which said element is capable.
 3. A lock and keycombination as set forth in claim 2 and wherein the lock cylinder andplug define therebetween a cylindrical interface, the tumbler meansincludes a plurality of diametrically shiftable plate tumblers which arespring-pressed so as to slide on the interfacial region of the lockcylinder, and said interfacial region is formed with twocircumferentially spaced longitudinal tumbler-receiving grooves, one ofwhich receives the tumblers when the plug is in its locked position andthe other of which receives the tumblers when the plug is in itsunlocked position.
 4. A lock and key combination as set forth in claim 1and wherein said spring means comprises a compression spring which isnested within a longitudinally and centrally disposed socket in theplug, the rear end of the spring bearing against the bottom wall of thesocket and the front end thereof bearing directly against the front endof the key ejector element.
 5. A lock and key combination as set forthin claim 4 and wherein the plug is of a composite nature and embodies afront plug part and a rear plug part having means releasably securingthe parts together in coaxial end-to-end abutting relationship, and thesocket within which the compression spring is nested is formed in saidrear plug part.
 6. A lock and key combination as set forth in claim 5and wherein said releasable securing means for the front and rear plugparts is in the form of a tongue and groove interlock connection betweenthe parts.
 7. A lock and key combination as set forth in claim 6 andwherein said interlock connection comprises a T-head on the rear plugpart and a conformable T-slot in the rear end of the front part.
 8. Alock and key combination as set forth in claim 5 and wherein the frontrim of the lock cylinder is provided with an annular recess therearound,the front end of the front plug part is provided with a rim flange whichseats within said annular recess, the rear plug part is provided with anexterior annular seating groove in the vicinity of the rear rim of therear plug part, and a snap ring seats within said latter groove and, incombination with said rim flange, serves to maintain the plug and lockcylinder in their assembled relation and against relative axiAlshifting.
 9. A lock and key combination as set forth in claim 8 andwherein both the key and the key ejector element are of flat plate-likeconstruction, are at all times coplanar, and the socket in which thecompression spring is nested is provided with a pair of diametricallydisposed grooves within which the opposite sides of the key ejectorelement is slidable.